Application of Membrane Separation Technology in Downstream Processing of Bacillus thuringiensis Biopesticide: A Review

Bacillus thuringiensis (Bt) has been extensively used in biopesticidal formulations due to its safe environmental and human health records. The widespread use of Bt is often challenged by production as well as formulation costs which are in direct contact with downstream processing, i.e. the separation/purification step. Downstream separation/purification efficacy governs the marketability of a product by affecting potency and aiding in further processing during formulation development. Separation/purification of Bt from fermentation broth is a crucial link between production and application and dictates economy, longer shelf life after formulation, ease of application and enhanced field efficacy. There are various methods like chemical precipitation, centrifugation and etc. which impede the efficacy of Bt recovery; however, all of them have their own limitations and drawbacks. In this regard, membrane separation technology has been recently introduced for downstream processing of the Bt biopesticide. This article comprehensively reviews recent advances in downstream processing of Bt based biopesticides incorporating the effect of different membranes and membrane processes.